Rubbing element for washboards



Feb. 7, 1933. H. J. GILBERT RUBBING ELEMENT FOR WASHBOARDS Filed Feb. 8,1952 K Z A Patentedk Feb. 7, 1933` UNITED STATES HARWOOD J'. GILBERT, OFSAGINAW, MICHIGAN,v ASSIGNOR TO `NATIONAL WASHBOARD COMPANY, OF CHICAGO,ILLINOIS, A CORPO'R'ATION-OF XVEST `VIRGINIA RUBBING ELEMENT FORWASHBOARDS Application led February 8, 1932. Serial No. 591,649.

This invention relates to wash-boards and pertains particularly to animproved rubbingr element.

The objects are to produce as an article of manufacture a sheet metalrubbing ele ment for wash-boards that can be made of thinnerA materialthan is customary and still have the necessary strength to resist thestrains brought upon it in use.

Another object is to provide a rubbing element that is of different andmore attractive appearance than those heretofore produced andconsequently more readily saleable.

Another obJect is to improve the effective-V ness of a wash-boardrubbingsurface by making it in such form that a larger number of bulges anddepressions will be encountered by the goods as they are rubbed up anddown along the face of the board, thereby increasing the effectivenessof its operation.

lVith the foregoing and certain other objects in view, which will appearlater in the specification, my invention comp-rises the devicesdescribed and claimed and the equivalents thereof. y

My invention consists in the rubbing element shown in the drawing. Fig.1 is a fragmentary front view of a wash-board having a rubbing surfacemade accordingto my invention.

Fig. 2 is a vertical sectional. view projected from Fig. 1. Fig. 3 is asection cn line 3-3 of Fig. 1.

Fig. 4 is a fragmentary sectional view on the line 4'4 of Fig. 1.

As is clearly shown in the drawing, the rubbing elementconsists in a.sheet of metal formed with horizontal parallel corrugations that presentalternating ribs 1 and grooves 2, their general shape in cross sectionbeing that of ogee curves. A series of parallel raised portions orwale-like ridges 3 winds diagonally and sinuously aci oss the crest ofeach rib 1.

A significant novel feature that distinguishes my present inventionresides in a structural modification of the diagonal wales 3 and of theside walls of the ribs 1. It is by this modification of ystructure thatthe stated objects of my invention are attained.

.According to Vmy improvement each of the diagonal wales 3 ischaracterized by being f divided in its length L into several individualwales 3 by the diagonal indentations 6 is to greatly increase the numberof bulges or projections 4, 5 rising from the rubbing surface of awash-board and to materially increase the strength and. stiffness of theribs 1 to resist pressure tending to collapse them in use, therebyenabling rubbing elements of adequate strength to be made from materialof less thickness than has been practicable heretofore.. The number ofeffective projections is greatly increased, giving improved washingefliciency.

Considered from the standpoint of appearance groove 6 performs anotheradvantageous function. It increases the amount of light reflected anddiffused by the rubbing surface, making the surface as a Whole while newappear much more brilliant and attractive to purchasers of wash-boards,thereby adding to the sale value of the article.

In practice my preferred mode of operation in making rubbing elementsthat are characterized by'the features just described is first, to passa thin sheet of metal through suitable embossing dies or rolls adaptedto form the sheet so it shall present a multitude of diamondorlozenge-shaped elements 7 separated from each other by diagonal grooves,as shown in Fig. 1. This embossed sheet is then passed through knowncorrugating rolls which produce the ribs 1, grooves 2 and also thediagonally disposed series of wales 3 on the crests of ribs 1. Each Wale3, however, due to those lozengeshaped raised portions 7 that occupyythe same space with it is divided lengthwise as shown in Figs. 3 and 4,and represents in general the pattern illustrated in Fig. 1, being theimproved rubbing element of my invention.

Having thus fully described my invention, what I claim and desire tosecure by Letters Patent is:

A rubbing element for Wash-boards comprising a sheet metal structurepresenting parallel ribs and grooves, said ribs having on their crestsparallel diagonally disposed alternating Wales and indentations, each ofsaid Wales consisting of a plurality of bulge elements separated bytransverse depressions.

In testimony whereof, I aflix my signature.

HARVVOOD J. GILBERT.

